Acoustical treatment has been used to enhance the acoustic quality of rooms and halls. Acoustical treatment is useful and largely necessary in both venues in which music is publicly performed, and in studios or other venues where music is recorded or even practiced. Without acoustical treatment, echoes, reverberation and other reflective features of venues can adversely affect the desired qualities of the sound.
A common form of acoustical treatment involves absorption. Absorption removes some or most of the undesired reverb or echo caused in venues with acoustically reflective walls. To this end, foam, fiberglass or other acoustically absorbent panels or devices are often disposed within the room at places where sound reflection is prevalent. Such absorbent panels operate to “deaden” the acoustic properties of the room.
One drawback of absorption techniques is that some of the higher frequency sounds can be de-emphasized. In many cases, this drawback is tolerable and worth the improvement from reverb and echo reduction. However, for certain types of music and sounds, absorption can provide a noticeable detriment. For example, acoustic stringed and percussion instruments can be significantly dampened by absorption equipment. For larger spaces, speech intelligibility can be negatively affected by over-absorption of high frequency energy.
To address this issue, moderate reverb and/or echo control can be achieved by another acoustical treatment involving sound diffusion. Sound diffusers are devices or systems that reflect and scatter incident sound waves to that the energy of the waves is diffused in many directions, as opposed to being concentrated. For example, the undesirable echo effects in rooms with large flat walls are caused by concentrated zones of reflected sound. Sound diffusers are shaped to reflect the sound in various directions to avoid or reduce concentrations. Because diffusers reflect sound, as opposed to absorbing sound, the sound is not deadened to the same degree, and high frequency energy is retained.
Currently, studios and performance halls must essentially select the absorption and/or diffusion desired for the venue. Because some types of music benefit more from diffusion and other types of music benefit more from absorption, it is difficult to have a single room that accommodates all types of music. Typically, a compromise must be arrived at that will be “good” for multiple applications, but potentially not “ideal” for a single one.